This invention relates to addition polymerizable aromatic sulfonium salts and to their polymers which polymers are useful as surface-active agents.
Organic surface-active agents are widely employed to provide stable aqueous dispersions for such commercial products as paper sizing compositions, floor waxes and polishes, latex paints and many other aqueous coating formulations. In most applications of these products, it is desirable to form a water-resistant protective film by applying the aqueous dispersion to a substrate and then drying the applied dispersion. Unfortunately, however, the desired water-resistance of such film is inherently weakened by the hydrophilic character of the surfactant that is retained in the film.
As shown in U.S. Pat. No. 3,409,660, elimination of lower water resistance caused by residual hydrophilic surfactant has been achieved by employing benzyl sulfonium salts. When polymeric films containing these benzyl sulfonium salts are heated and/or dried, the salt decomposes to form volatile sulfides and a low-molecular weight, non-polymeric hydrophobic residue. Unfortunately, the volatile sulfides have unpleasant odors. In addition, the low-molecular weight residues act as plasticizers and can often be extracted from resulting dried films or coatings; thereby rendering them unsuitable for packaging or otherwise contacting foodstuffs. Thus, use of aqueous dispersions containing these benzyl sulfonium salts is significantly limited.
In view of the aforementioned deficiencies of conventional surface-active agents (e.g., surfactants, emulsifiers and dispersants), it would be highly desirable to provide novel surface-active agents which do not yield hydrophilic residues or odorous vapors when subject to heating and/or drying conditions.